condition mean min max ZT0-3 3.05 3.05 3.05 ZT4-7 2.0 2.0 2.0 ZT8-11 4.9 4.9 4.9 ZT12-15 2.85 2.85 2.85 ZT16-19 3.1500000000000004 3.1500000000000004 3.1500000000000004 ZT20-23 4.95 4.95 4.95